1. Field of the Invention
The present invention relates to an a.c. generator for a vehicle which is equipped in, for example, a passenger car or a truck.
2. Discussion of Background
A conventional a.c. generator for a vehicle is disclosed in, for example, JP-B-2927288. In this conventional technique, a plurality of substantially U-like conductor segments are used as a stator coil. In slots of the stator, the conductor segments are paired as an inner layer and an outer layer along depth directions of the slots to be a single pair or a plurality of pairs and arranged in the slots in a state that the conductor segments are mutually insulated. Outside of the slots, the conductor segments are arranged by protruding from an end surface side of the stator core, wherein a coil end group mainly has repeating serially connected patterns, by which different layers in the separated slots are serially connected in correspondence with an NS magnetic pole pitch of a rotator.
At a coil end, the plurality of the conductor segments are arranged interposing intervals so as to cross a ventilating direction of a cooling air in a frame, whereby the cooling air flows by crossing the plurality of the conductor segments at the coil end.
In other words, in this conventional technique, because the conductor segments are mutually separated at the coil end and the cooling air passes across the plurality of the conductor segments at the coil end, it is aimed to improve cooling of the coil end to thereby obtain a high output.
In the above conventional technique, because the conductor segments at the coil end of the stator coil are separately arranged interposing spaces therebetween, there is problems that a short occurs by a contact between adjacent coils at the coil end or between joining portions of the adjacent coils in receipt of vibrations from an engine to thereby decrease the output and generate noises.
Further, there are problems that the joining portions at the coil end are disconnected by the vibrations of the a.c. generator and that a temperature excessively increases by a connection resistance as a result of a crack.
Further, there is a problem of wind noise caused by uncomfortable high order interference sound between an edge of a molten joining portion of the coil end caused by welding and an edge of a claw-like magnetic pole of a rotator or a fan occurs because the coil end of the stator coil is positioned on a discharge side of a the cooling air.
Further, there is a problem that high order wind noise occurs because of cooling air passing through a gap between coils at the coil end of the stator.
Incidentally, in JP-A-11-164505, it is disclosed that insulation is assured by providing a gap between coils at a coil end of a stator coil. However, there is a problem that the insulation is spoiled when an extraneous matter intrudes between the coils and the coil is deformed by a collision of the extraneous matter.
It is an object of the present invention to solve the above-mentioned problems inherent in the conventional technique and to provide an a.c. generator for a vehicle which improves insulation at a coil end of a stator coil, keeps vibration proof, and reduces wind noise.
According to a first aspect of the present invention, there is provided an a.c. generator for vehicle, in which a resin is disposed in a coil end of a stator coil and a gap between coils at the coil end is clogged.
According to a second aspect of the present invention, there is provided the a.c. generator for a vehicle, in which a resin is disposed on an inner peripheral surface of the coil end of the stator coil to clog a gap between coils.
According to a third aspect of the present invention, there is provided the a.c. generator for a vehicle, in which a resin is disposed on an entire periphery of the inner peripheral surface and of an outer peripheral surface of the coil end of the stator coil to clog a gap between the coils.
According to a fourth aspect of the present invention, there is provided the a.c. generator for vehicle, in which a resin is disposed on surfaces of coils forming the coil end of the stator coil to clog a gap between the coils.
According to a fifth aspect of the present invention, there is provided the a.c. generator for vehicle, in which the surfaces of the coil end of the stator coil is formed to be plane without any unevenness by the resin disposed in the coil end of the stator coil.
According to a sixth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein on a surface of the stator coil at the coil end, a protrusion is formed by the disposed resin.
According to a seventh aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the resin is disposed at coil ends on both sides in an axial direction of the stator coil.
According to an eighth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein a conductor segment has a substantially U-like shape, and the stator coil has a coil end on a side of connecting the substantially U-like segments and another coil end on a side of bending the substantially U-like segments.
According to a ninth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein a blower means is a fan provided in an end portion of the rotator.
According to a tenth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the fan is lapped in the coil end of the stator coil in peripheral directions of the fan.
According to an eleventh aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein fans are provided on both sides of end portions of the rotator, respectively opposite to the connected side and the bent side of the coil ends, and a commutator is provided on the bent side.
According to a twelfth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein an air flow received by the coil end on the connected side of the stator coil is larger than that received by the coil end on the bent side.
According to a thirteenth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the number of blades of the fan opposite to the coil end on the bent side is larger than the number of blades of the fan opposite to a coil end on the connected side.
According to a fourteenth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the maximum height of the blades of the fan on the bent side is larger than the maximum height of the blades of the fan on the connected side.
According to a fifteenth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein spaces formed between base plates of the fan on the bent side are substantially shielded by an end surface of the magnetic poles of the rotator.
According to a sixteenth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein a separator is provided between recessed portions of the magnetic poles on a side of the commutator in the rotator and a bottom portion of the fan.
According to a seventeenth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the conductor segments are formed by a flat rectangular coil.
According to an eighteenth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein an insulating paper is provided to insulate the stator core from the stator coil and also insulate the stator coils from each other in the slots of the stator, and the stator coil is a bare wire.
According to a nineteenth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the resin is mainly composed of an epoxy resin.
According to a twentieth aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein an additive having heat conductivity larger than that of the resin is mixed in the resin.
According to a twenty-first aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the resin is disposed in the coil end by powder coating.
According to a twenty-second aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the resin is disposed in the coil end by fluidization dip.
According to a twenty-third aspect of the present invention, there is provided the a.c. generator for a vehicle, wherein the resin is a single liquid type dried at an ordinary temperature.